Tags or markers, for example RFID tags, may be used for many different applications, in particular in the fields of logistics, maintenance and access control. In this connection, such tags may be attached to product packaging or to the product itself. It is also possible for such tags to be integrated in a product. Goods or products provided with tags may be tracked in a logistical chain in which the goods pass through different locations, enterprises and systems. Tags are read by associated tag reader systems or readers. The presence of a tag or the detection of a tag represents an event. This event may consist, for example, of an elementary base event in the form of a data access to the tag or an application-specific event of an application program. If a tag is read by a reader, this represents on the one hand a base event in the form of a data access to the tag and on the other hand may also represent an event on an application plane, for example goods inward in a warehouse. For the purpose of their evaluation the events are supplied to the application program, which may be executed on a different computer from the reader. For example, an application event is evaluated by means of an application program running on a remote target computer. In conventional systems such events which are triggered by a tag are selectively forwarded by the reader to a target computer provided for that purpose. The event message is switched by the reader to a target computer of the background system, which evaluates the event message.
A considerable drawback of such systems is that they are totally inflexible. If, for example, the system is reconfigured such that the application program for evaluating an event is executed on a new and/or different computer, it may be necessary to reconfigure the forwarding of the event message by the reader so that the event messages are redirected or switched to the new target computer. This reconfiguration of the event forwarding represents a considerable overhead. Moreover, such a reconfiguration is very susceptible to error and results in event messages being forwarded incorrectly. It may therefore happen that an application program which is executed on a new target computer does not receive a necessary event message and thus delivers an incorrect evaluation result. Moreover, there is the possibility that unauthorized third parties will intentionally divert event messages in order to manipulate their evaluation.